The Great White Hope (Pre Project Thread)

[Erik Sine]

UPDATED 10.13.08

This is the first project to be placed into the Tutorial section of this board. The Tutorial section of this board is reserved for those members who choose to support this board by upgrading their free membership, to that of a "Board Patron". Also, this section is for Members who are sign component manufacturer's, suppliers, distributors, or associations and choose to become a "Board Vendor". The future of the Tutorial section will hold more projects along with Articles written by various individuals.

This Tutorial Section is our way of saying, "Thank You for supporting the website, and here's something back."

For updates, further content information and results will now be put into the Tutorial Section for this project seen here, in the Fabrication category "Great White Hope (Part I&II)

To view this project and monitor the durartion, go to your profile control "My Control's" > Menu > Paid Subscriptions. or CLICK HERE

Now we'll give this it's own thread for the board project we will be doing on building a sign cabinet simulating a channel letter stroke. Were going to have individual sections within this cabinet of 8" x 3' & 5" deep to simulate double stroke.

My next question for LED's are, should we stick to 12-15v power sources or should anything go? Higher? I would just like to use the best white made for channel letters a manufacturer has.

I'd like to stick with 30ma transformers for neon. I'd like to use EGL's CL71 and of course the (Insert best super hero voice here) Elite 65D, maybe even a 6500 white

To repeat from an earlier thread.

The Standard for this project will be 6500 Kelvin

POWER SOURCES

• All sections will be on a dedicated power source, for LED's use the same? Is that important?
  
• For neon I'd like to use either France, Ventex or Tech 22's
  
• All individual sections will have it's own dedicated P3 Kill-A-Watt Meter, maybe Telford can test with his meter too.
  

ACRYLIC FACE

• 7328 White
  

TESTING (3 Factors)

• Initial brightess (Light Meter on the acrylicmeasuring nits)
  
• Brightness over time (1 Year for 6 hours a day, retested bi-monthly)
  
• Power consumption (Watt Meter)
  

COMPONENT VOLUNTEER LIST

• ABC Sign Products (Knock Down Kit)
  
• Ventex Technologies (Electronic Transformers)
  

LED VOLUNTEER LIST (To Date)

• YYZ Systems
  
• Axiom
  
• Agilight
  
• GE Tetra
  
• Philips Affinium LED String
  
• SloanLED
  
• Ventex VenBrite
  

NEON VOLUNTEER LIST

• Elite Lamp Technologies
  
• EGL
  

The results will be posted in the tutorial section and not in the public open forum. The tutorial section is accessible by "Board Vendors & Board Patron's". All Vendors volunteering their products (LED's/Neon) will be given access in a limited form where Vendors who would like to contribute more such as power supplies will be given a year "Board Vendor" membership and all the perks that come with it.

Though there is a "Volunteer" list, I will be applying various manufactured products to the cabinet.

ABC Sign Products will be building and sending out the 5" deep Extrusion knock down kit which we'll weld up and put in divider bars and attach the Watt meters.

If any vendors would like to participate in this project please post a reply here or PM me. Other light sources are welcome as well if it can be used for channel lettering, it does not necessarily have to be the typical LED Neon light *COUGH* errr, Cold Cathode light source.

If I forgot any details I'll keep you updated, I may have forgotten something but it's 100 here, it's saturday and I'm sweatin as I'm typing this out and in danger of electrocution by finger tips.

[YYZ]

I would think that any of the YYZ / Axiom / Agilight modules would perform well next to each other. I strongly recommend using product from Sloan, USLed, Gelcore and Permlight as well - since these are the more well known and widely used brands - so more users will have a point of comparison for the brightness. ie: sign shop X who uses mostly Sloan can understand how bright every product is in relation to a known quantity, to them. sign shop Y who used mostly Gelcore, can do the same, etc... If you can get other secondary stuff like CAO, France, Lumificient, etc - it would make this an incredibly thorough investigation.

So each system/brand will light up 8" x 36" with a depth of 5"? Face material doesn't matter as long as it's the same one for all, for benchmarking purposes. Using a 1/8" sign white will most closely reflect a typical white channel letter, though, as the satin ice is still a specialty item.

If you are using a Watt meter for each product, then you'll need a separate PSU for each brand, as you've described. I think only Gelcore and Axiom may require you to use a special PSU as the rest listed run at 12VDC. I'm just happy you'll be making these measurements though a face material - which is most important when measuring light for the sign industry - but you may also wish to do a comparison of "with face / without face" to demonstrate what % of light actually escapes through the face - as this will vary a little depending on color temperature and technology. While you probably won't get in a Kelvin meter, you may wish to also comment about the color tone of each particular product, as some will be more blue, as well as comment about consistency of light on the surface as some may show hotspots, etc..

What is your timeframe on this? I would think every company could afford to donate the ~$100~ or so of material for your testing, if you contact the right person in the company and explain who else is offering samples for evaluation and that if they don't donate, their product will be purchased and included in the comparison anyways (so there is no way to avoid having your system benchmarked against the rest).

I'm sure I'll think of more...

[YYZ]

Oh, and one more thing. Perhaps if you're going to all this effort - you may want to determine "how bright is bright enough".

What I mean by this, is that you will have a variation of systems and brightness levels, but by moving back to a distance of say 100' and lighting them one at a time, you can perhaps determine which products you feel hit the sweet spot in terms of proper brightness for a white letter, or which meet what you feel is the minimum recommended level for a sign to get the proper attention. Some will be lower, some may exceed, but you might decide that anything less than XX footcandles (measured on the face) is not adequate, for example - and then make a comparison stating that "to achieve an appropriate level of XX foot candles, you would need ## number of modules which would then consume ## watts of power".

Follow?

[Erik Sine]

Though there is a "Volunteer" list, I will be applying various manufactured products to the cabinet.

I have my list of the usuals that will be used, I'm trying to get volunteers first

I would think that any of the YYZ / Axiom / Agilight modules would perform well next to each other. I strongly recommend using product from Sloan, USLed, Gelcore and Permlight as well - since these are the more well known and widely used brands - so more users will have a point of comparison for the brightness. ie: sign shop X who uses mostly Sloan can understand how bright every product is in relation to a known quantity, to them. sign shop Y who used mostly Gelcore, can do the same, etc... If you can get other secondary stuff like CAO, France, Lumificient, etc - it would make this an incredibly thorough investigation.

So each system/brand will light up 8" x 36" with a depth of 5"? Face material doesn't matter as long as it's the same one for all, for benchmarking purposes. Using a 1/8" sign white will most closely reflect a typical white channel letter, though, as the satin ice is still a specialty item.

If you are using a Watt meter for each product, then you'll need a separate PSU for each brand, as you've described. I think only Gelcore and Axiom may require you to use a special PSU as the rest listed run at 12VDC. I'm just happy you'll be making these measurements though a face material - which is most important when measuring light for the sign industry - but you may also wish to do a comparison of "with face / without face" to demonstrate what % of light actually escapes through the face - as this will vary a little depending on color temperature and technology. While you probably won't get in a Kelvin meter, you may wish to also comment about the color tone of each particular product, as some will be more blue, as well as comment about consistency of light on the surface as some may show hotspots, etc..

What is your timeframe on this? I would think every company could afford to donate the ~$100~ or so of material for your testing, if you contact the right person in the company and explain who else is offering samples for evaluation and that if they don't donate, their product will be purchased and included in the comparison anyways (so there is no way to avoid having your system benchmarked against the rest).

I'm sure I'll think of more...

As far as the light measurements, I thought at the sign face will be the best since most don't explain where they get their numbers.

[manuellynch]

I agree with Marko - should we set designer white 71 neon as the benchmark - it is what the world refers to as "the brightest"

I have one odd thing to throw at you - our AXLE3WG65-3 module will probably only need one stroke on an 8" letter.

On your testing proposal - we have the same setup for a letter running for well over a year using both Axiom AXLE4 and AXLE1WG series and have shown less than 2% degradation of light output...only differences is that they are running 24 hours a day and the temperature extremes go from 32F to 120F.

You live in San Diego - how can the samples see "real temperature"? Send some to Marko to see how they do in cold (-30F).

And Marko - "using the more popular brands like Sloan, Permlight, GE" - I can say that several people on this board that include the top 10 sign companies in the USA that were the largest customers for Sloan or Permlight have switched completely over to Axiom. GE...well we are trying to get them in a few places but hell I dont have GE Finance to help me loan a large sign company funds to build a new factory in the USA.

[Erik Sine]

At night when this cabinet will be on, it will be in 100+ temps during the summer and cooler during the winter

Temperature will play a completely different role outside of this project with this being set up in San Diego. Results would vary of course from Death Valley To Alaska, that would all depend on where a sign is going, that would have a be a different project all together, but wouldn't mind doing something like that in the future.

I would encourage vendors to send the samples in their own layout pattern, preferred quantity or according to advertising configs. I choose 8" because most will tend to configure two rows of glass. Some sign makers can use a tri-phosphor white single stroke at 8" being 15mm glass. But I don't know who's going to use 15mm for their section. EGL might, but I think Elites going to use 13 or 12mm or even smaller diameter, don't know, can't speak for them. I know I don't ever use 15mm myself.

Also forgot to add. I want everyone to send me twice the light source layout material, so I can test the unused spare at the end of one years time to be a little more accurate.

[TelfordDorr]

Now we'll give this it's own thread for the board project we will be doing on building a sign cabinet simulating a channel letter stroke. Were going to have individual sections within this cabinet of 8" x 3' & 5" deep to simulate double stroke.

NEON VOLUNTEER LIST (To Date)

• Elite Lamp Technologies
  
• EGL
  

Let me know when you're ready and I'll bring a wattmeter...

TD

[imanut]

I have one odd thing to throw at you - our AXLE3WG65-3 module will probably only need one stroke on an 8" letter.

I hate it when "will probably only need" ----------is used.

On choices of white --- I personally think that 6500 white needs to be used as a "standard" and then go on from there. Why? Because that truly is the standard by which even egl 71 is compared. Depending on whether you're looking at "color", "brightness", or "enough" as in even light as the defining terms. Since perceived color is totally up to the client, and brightness is not a measureable term, "enough light" comes into play quite often. What you'll find in this sample test---is that "colors" are all over the place. Visual "brightness" is all over the place. And "enough" light is hard to determine. 6500 white ------has a range of Kelvin color. Led's are all over the place. If you turn on ANY letter, lit up by whatever your favorite choice is ---------- it usually looks pretty good. When you light up a second, and can compare----now the choices come in. Is it "whiter"? Meaning what----a bluer white, or a milky white. Your preference for the best is the determining factor. Leaving "brightness" out since it can't be measured, and looking instead at lux or lumens-----is there really enough difference to really care about? So, then, is it bright enough? IF instead, you set up a letter at one end of a dark room, and another at the other end of the room -------------- and then had to judge back and forth, rather than a side by side comparison ---------- the answers wouldn't be quite so evident.

To compound all this --------in your samples. MOST led mfgs have different leds for different faces, and different choices for how much your cus;tomer wants to spend. Should we use the cheap axioms, or the more costly. The cheaper Sloan, or the more expensive Sloan, the cheaper Gelcore, or the more expensive ----------- and then, ask yourself why that particular one.

One of the absolute best demos had virtually ALL the led's in samples--------and you could truly pick and choose which ones you wanted to light up and compare ---------- made some look pretty darn sick which comparing side by side.

gn

[manuellynch]

I have one odd thing to throw at you - our AXLE3WG65-3 module will probably only need one stroke on an 8" letter.

I hate it when "will probably only need" ----------is used.

On choices of white --- I personally think that 6500 white needs to be used as a "standard" and then go on from there. Why? Because that truly is the standard by which even egl 71 is compared. Depending on whether you're looking at "color", "brightness", or "enough" as in even light as the defining terms. Since perceived color is totally up to the client, and brightness is not a measureable term, "enough light" comes into play quite often. What you'll find in this sample test---is that "colors" are all over the place. Visual "brightness" is all over the place. And "enough" light is hard to determine. 6500 white ------has a range of Kelvin color. Led's are all over the place. If you turn on ANY letter, lit up by whatever your favorite choice is ---------- it usually looks pretty good. When you light up a second, and can compare----now the choices come in. Is it "whiter"? Meaning what----a bluer white, or a milky white. Your preference for the best is the determining factor. Leaving "brightness" out since it can't be measured, and looking instead at lux or lumens-----is there really enough difference to really care about? So, then, is it bright enough? IF instead, you set up a letter at one end of a dark room, and another at the other end of the room -------------- and then had to judge back and forth, rather than a side by side comparison ---------- the answers wouldn't be quite so evident.

To compound all this --------in your samples. MOST led mfgs have different leds for different faces, and different choices for how much your cus;tomer wants to spend. Should we use the cheap axioms, or the more costly. The cheaper Sloan, or the more expensive Sloan, the cheaper Gelcore, or the more expensive ----------- and then, ask yourself why that particular one.

One of the absolute best demos had virtually ALL the led's in samples--------and you could truly pick and choose which ones you wanted to light up and compare ---------- made some look pretty darn sick which comparing side by side.

gn

Let me clear that up - you only need one stroke of Axiom AXLE3WG65-3 for an 8" stroke. But then again Gary at your company you dont get to use the products that make the most amount of sense as you have to see what Monigle specifies. And do they build signs in their shop????

I have a real problem with LED module manufacturers dictating to sign companies how to build a sign or the layout to provide. That is incredibly egotistical of an LED module manufacturer to think they "know how to build a sign" better than someone who has been doing it for years.

Gary - you guys make signs, we make lights. I dont presume that you should know anything about Thermal Conduction or W/mK of a material, or what the reflow temperature is of a particular LED is...and I am not going to assume you want to learn about binning structures or the transmisivity of certain materials and how they may block certain wavelenghts of light. No different than you are not going to tell me why riveting a channel return rather than stapling may be better - or why a stainless steel halo lit letter seems to run hotter than a comparable aluminum letter.

Simply put Gary - our new LED system is FRIGGIN BRIGHT and runs cooler than any other product on the market - and ironically uses an LED technology that is capable of handling more heat than anyone could believe - the LED on our product can handle a junction temperature of 125C (the human body runs at 37C and we interpret 57-60C as "burning"). So essentially our LED could physically burn you but still operate just fine.

6500K +/- what %? Do you buy neon that way?

And Gary it is your management choice not to make more money using a product that is more than 1/2 the price. Some companies have gotten a lot smarter and done their extensive engineering analysis and determined that our products quality/reliability and performance are the same or better than the others but just cost a lot less. They either pass that onto customers or split the difference with customers and make more money.

[YYZ]

I know 6500k is the supposed "correct white", but we actually sell more of our 5500k product for sign jobs than anything else. It is not only a more appealing white, it is also a better color for backlighting faces of varying colors, such as those with Pantone vinyls, etc. 6500k (or the range around it) is just too blue in most cases, whether LED or neon.

As for the "enough" comment - I was simply saying that Erik will be in a unique position to have many light sources at his disposal and can make some sort of judgment on what he feels (or whoever else can share an informed opinion after looking at the demos) should be a "recommended guideline for white letters", be that 80 foot candles, 120 foot candles, whatever. All the light sources will have their outputs listed and then readers can decide for themselves which vendor's "user guide" makes most sense and which product they feel most comfortable using to achieve their sign needs.

The DOT has some sort of NIT rating for the reflectance of road signs, but to my knowledge, the ISA has not set a benchmark for what is effective "white light" for signs. If this comparison is thorough enough, one of the magazines may take up the cause and publish the results, which could result in de facto standards being accepted by the sign community.

As for cheaper vs better - it usually comes down to letter size. Smaller letters need smaller modules, which have less light. That's why LED mfr's offer a choice. If some sign co's want to use the smaller modules in bigger signs, that's up to them. I see it more often than I like, but I can understand about keeping costs down - though in some cases they are just plain cutting corners because they're cheap. It's still better to use a domestic brand 'cheaper' module than offshore crap like CAO or LedInc.

[imanut]

Correct color being 6500 K??? I didn't say that-------What I said was that it would probably be more considered as the "standard". Personally, I always liked the 4500. That used to be standard millions of years ago. And then 6500K came along. Manny asked, and I'm not sure if he was being facetious or not, as to whether we "buy" neon in a range of K. If he was referring to buying 4500, or 6500, or 7100, then obviously yes. If he was referring to the range of K that a mfg decides that 6500 is in --------no, I don't, but you can't tell me that Voltarc 6500 matches EGL 6500 either.

When I referred to "enough" ---- it wasn't that Eric wouldn't have enough choices --- it's just that enough light becomes more into the equation in what a particular customer wants based on price - and often that trumps brightness, and color of white.

And Manny, I personally feel that an LED mfg should be involved in deciding which of their many products should/should not light up a particular letter, much in the same way that Eric should rely on his tube bender to help in the decision process, regardless of whether the decision is millimeter of glass, or the correct color to use, or the proper layout of the tubes.

Personally, cheapest is not always the best way to decide a product - any product, or any service. And when you speak of Monigle or whomever spec'ing out products - obvious they do. But, we also get our fair share of clients that come in and look at our board of letters, with plex, with neon, with different LED's ---------- and they get to pick based on what it is that THEY are looking for with guidance, rather than someone deciding what they need based on price, or someones decision on which is the best white, or someones decision that brightest is the cure-all for whatever ails. That's why your product is on the board like everyone else's.

Quite simply, depending on the size of the sign shop, the customer involved, etc ---- choices for the client are often times dictated by the company that makes the sign, and quite often are based on the bottom line concerns of the sign company ---thus the price of the components alone---and that is not often the best choice for decisions.

gn

[Erik Sine]

I need to know how many slots people need for this cabinet.

So far I have 1 slot for 15mm 6500 white.

One slot for Elite Lamp.

YYZ, EGL, Axiom, AgiLight? I imagine one only, but you may have another product line.

I haven't got any relies back from Permlight, GE, Sloan, and a few others.

[YYZ]

It depends what you want. We do have the brighter product with the higher wattage, but it isn't reflective of what we sell the most, nor what customers are wanting to buy as the market in general is getting more price sensitive. Our newest PowerStroke module is down to less than a watt, powering 3 quad-chip LEDs. It uses less power, runs cooler and is cheaper while providing 90% of the light we got out of the previous 1.8W module - so the intention was to run with it as a flagship product... this will be what I'd prefer to send, but if you'd like to include it for comparison purposes then I'm happy to include the higher power, higher brightness model. We really should sell these for the really big letters.

If you have room for 2 slots for YYZ, then I'm sure Axiom and EGL could provide a good/better product also (say standard 15mm white alongside the tri-phosphor, since it is still very widely used).

[Erik Sine]

Are you going to send your 3.5 watt module?

[YYZ]

It's actually a 3.0W module, but yes, I can send these also if you like. The 1.0W module will be the main seller though, and has a better lumen per watt rating. It's more than bright enough for most letters, though the 3.0W is available as a premium upgrade when maximum light is more important than cost or power (day/nite material, etc).

Have you started the process with building this thing? I may actually need to be in SoCal again in late July or early August and would love to see the thing in person if it would be ready by then.

[Goatboy]

With LEDs generally we use Milky white to prevent spotting. Hardest part about this would be not only how bright but also how material friendly. So heres the only problem I have with this test box. Im sure Im probably one of the few but

"Temperature will play a completely different role outside of this project with this being set up in San Diego. Results would vary of course from Death Valley To Alaska, that would all depend on where a sign is going, that would have a be a different project all together, but wouldn't mind doing something like that in the future."

We are in opposites of the Neon/LED spectrum. White Neon is a big no-no here, actually, anything but red for exterior use is. You can do it but the results are generally poor if your lucky. In the summer neon generally is burning 1-2 hours(between 3-4 am) at most a day down south here in Anchorage, none at all farther North. When neon gets its full use we generally hit an average of 19(23 at solstice) hours of dark with our temp valley ranging from 25 to -40, again this is the southern part of the state...up north...really dont want to think about it but -80 is not uncommon. LEDs thrive in cold climate neon thrives in hotter. Guess the point is very cool idea but I believe temp is more crucial then may be put in for in a test like this

[Erik Sine]

I'd like to rap up the amount of slots byt mid week next week and get it rolling.

But I'd like to state, this project is not all about power consumption, or brightness. It's about practicality to applications.

Goat, I've never been to Alaska but do you have a lot of indoor shopping centers with those temps? Also, what diameter glass have you used up there when you used it for outdoors?

[manuellynch]

I agree with Marko - three slots would be great.

Also - Marko let me know when you are going in July or August and I may go at the same time and meet up with you guys.

[Goatboy]

Generally 13mm to 15mm glass. We have a total of 2½ malls in Anchorage most of which have various neon projects in them. That in mind malls are easy due to climate controlled enviroments. I really like the idea of this experiment. I think we as a company should try one ourselves in our elements to get the other side.

[JR Neon]

I wonder what percentage electric signs are in frigid zones versus milder climates. Cool for ABC to supply the cabinet

[whistler]

Correct color being 6500 K??? I didn't say that-------What I said was that it would probably be more considered as the "standard". Personally, I always liked the 4500. That used to be standard millions of years ago. And then 6500K came along. Manny asked, and I'm not sure if he was being facetious or not, as to whether we "buy" neon in a range of K. If he was referring to buying 4500, or 6500, or 7100, then obviously yes. If he was referring to the range of K that a mfg decides that 6500 is in --------no, I don't, but you can't tell me that Voltarc 6500 matches EGL 6500 either.

When I referred to "enough" ---- it wasn't that Eric wouldn't have enough choices --- it's just that enough light becomes more into the equation in what a particular customer wants based on price - and often that trumps brightness, and color of white.

And Manny, I personally feel that an LED mfg should be involved in deciding which of their many products should/should not light up a particular letter, much in the same way that Eric should rely on his tube bender to help in the decision process, regardless of whether the decision is millimeter of glass, or the correct color to use, or the proper layout of the tubes.

Personally, cheapest is not always the best way to decide a product - any product, or any service. And when you speak of Monigle or whomever spec'ing out products - obvious they do. But, we also get our fair share of clients that come in and look at our board of letters, with plex, with neon, with different LED's ---------- and they get to pick based on what it is that THEY are looking for with guidance, rather than someone deciding what they need based on price, or someones decision on which is the best white, or someones decision that brightest is the cure-all for whatever ails. That's why your product is on the board like everyone else's.

Quite simply, depending on the size of the sign shop, the customer involved, etc ---- choices for the client are often times dictated by the company that makes the sign, and quite often are based on the bottom line concerns of the sign company ---thus the price of the components alone---and that is not often the best choice for decisions.

gn

[whistler]

I have one odd thing to throw at you - our AXLE3WG65-3 module will probably only need one stroke on an 8" letter.

I hate it when "will probably only need" ----------is used.

On choices of white --- I personally think that 6500 white needs to be used as a "standard" and then go on from there. Why? Because that truly is the standard by which even egl 71 is compared. Depending on whether you're looking at "color", "brightness", or "enough" as in even light as the defining terms. Since perceived color is totally up to the client, and brightness is not a measureable term, "enough light" comes into play quite often. What you'll find in this sample test---is that "colors" are all over the place. Visual "brightness" is all over the place. And "enough" light is hard to determine. 6500 white ------has a range of Kelvin color. Led's are all over the place. If you turn on ANY letter, lit up by whatever your favorite choice is ---------- it usually looks pretty good. When you light up a second, and can compare----now the choices come in. Is it "whiter"? Meaning what----a bluer white, or a milky white. Your preference for the best is the determining factor. Leaving "brightness" out since it can't be measured, and looking instead at lux or lumens-----is there really enough difference to really care about? So, then, is it bright enough? IF instead, you set up a letter at one end of a dark room, and another at the other end of the room -------------- and then had to judge back and forth, rather than a side by side comparison ---------- the answers wouldn't be quite so evident.

To compound all this --------in your samples. MOST led mfgs have different leds for different faces, and different choices for how much your cus;tomer wants to spend. Should we use the cheap axioms, or the more costly. The cheaper Sloan, or the more expensive Sloan, the cheaper Gelcore, or the more expensive ----------- and then, ask yourself why that particular one.

One of the absolute best demos had virtually ALL the led's in samples--------and you could truly pick and choose which ones you wanted to light up and compare ---------- made some look pretty darn sick which comparing side by side.

gn

I find you comments interesting. Based on this it seems that the standard hasn't been established although most seem to default to 6500K. I'm just starting to see the advantages of the different color temps depending on the face color and materials.

[YYZ]

I find you comments interesting. Based on this it seems that the standard hasn't been established although most seem to default to 6500K. I'm just starting to see the advantages of the different color temps depending on the face color and materials.

Generally speaking, 6500k White is common because it's the best compromise between brightness as color quality. The "bluer" you go, the higher the brightness (based on equal power). The "warmer" you go, the lower the light output.

From a usage standpoint, 6500k is on the blue side for most, but not unlike moonlight, which most people's eyes are used to at night - and visual acuity is actually better with a higher k temperature (this is why visibility under metal halide lamps is sharper than under sodium lamps, for example). It's a better color for backlighting blue, purple, etc.

Our 5500 (nominal, usually 5300-5400) is a much nicer "actual white" which I would consider "sign white", as it is closer to the color of a Daylight Fluorescent lamp than 6500k neon, even though a Daylight lamp is actually supposed to be 6300k. My experience is that most neon and/or LEDs that sell as a 6500k are actually cooler, some pushing 7000k and beyond. A white in the 5300-5500 range is still going to give you a nice punchy white, but also be able to backlight pretty much any color in the spectrum, especially brighter colors. It goes right from red to yellow to green to blue with no trouble because of the higher CRI.

Once you get into even warmer colors (the range between 4400 and 5200 is seldom used), your output drops further still, and is useless at illuminating blue, purple, etc. You get nice neutral white (3500 - 4100, like most halogen lamps), what I call designer white (3000 - 3400) and warm white (2600 - 2900) that replicate incandescent light... these are seldom used for illuminating channel letters, but for backlighting a large format images, posters, etc - anything between 3500 and 5500 will do a much better job than 6500k light sources. We're working on a large airport project that is using a 12 color printing process for the digital prints, and 5300k was deemed to be the perfect white source for backlighting.

[manuellynch]

Generally speaking, 6500k White is common because it's the best compromise between brightness as color quality. The "bluer" you go, the higher the brightness (based on equal power). The "warmer" you go, the lower the light output.

From a usage standpoint, 6500k is on the blue side for most, but not unlike moonlight, which most people's eyes are used to at night - and visual acuity is actually better with a higher k temperature (this is why visibility under metal halide lamps is sharper than under sodium lamps, for example). It's a better color for backlighting blue, purple, etc.

Our 5500 (nominal, usually 5300-5400) is a much nicer "actual white" which I would consider "sign white", as it is closer to the color of a Daylight Fluorescent lamp than 6500k neon, even though a Daylight lamp is actually supposed to be 6300k. My experience is that most neon and/or LEDs that sell as a 6500k are actually cooler, some pushing 7000k and beyond. A white in the 5300-5500 range is still going to give you a nice punchy white, but also be able to backlight pretty much any color in the spectrum, especially brighter colors. It goes right from red to yellow to green to blue with no trouble because of the higher CRI.

Once you get into even warmer colors (the range between 4400 and 5200 is seldom used), your output drops further still, and is useless at illuminating blue, purple, etc. You get nice neutral white (3500 - 4100, like most halogen lamps), what I call designer white (3000 - 3400) and warm white (2600 - 2900) that replicate incandescent light... these are seldom used for illuminating channel letters, but for backlighting a large format images, posters, etc - anything between 3500 and 5500 will do a much better job than 6500k light sources. We're working on a large airport project that is using a 12 color printing process for the digital prints, and 5300k was deemed to be the perfect white source for backlighting.

Great post Marko. Only one addition - Warm White 2700K is usually used for halo lit letters in historic or older parts of town where the backdrop is a natural element like stone or brick. Warm white renders red and earth tones better.

Only other thing to note is that visual acuity of people over 50 changes and as you get older you tend to perceive cooler white (6500K) as much brighter than warmer white even if they are the exact same lumen output.

Also - younger generations that have been raised on energy efficient lighting in schools, home etc typically call cool white light sources "clean" and perceive warm white lighting to be "dirtier"...this was from a survey done by a national home builder who is trying to come up with a new home product that caters to the younger audience.

[imanut]

Generally speaking, 6500k White is common because it's the best compromise between brightness as color quality. The "bluer" you go, the higher the brightness (based on equal power). The "warmer" you go, the lower the light output.

From a usage standpoint, 6500k is on the blue side for most, but not unlike moonlight, which most people's eyes are used to at night - and visual acuity is actually better with a higher k temperature (this is why visibility under metal halide lamps is sharper than under sodium lamps, for example). It's a better color for backlighting blue, purple, etc.

Our 5500 (nominal, usually 5300-5400) is a much nicer "actual white" which I would consider "sign white", as it is closer to the color of a Daylight Fluorescent lamp toohan 6500k neon, even though a Daylight lamp is actually supposed to be 6300k. My experience is that most neon and/or LEDs that sell as a 6500k are actually cooler, some pushing 7000k and beyond. A white in the 5300-5500 range is still going to give you a nice punchy white, but also be able to backlight pretty much any color in the spectrum, especially brighter colors. It goes right from red to yellow to green to blue with no trouble because of the higher CRI.

Once you get into even warmer colors (the range between 4400 and 5200 is seldom used), your output drops further still, and is useless at illuminating blue, purple, etc. You get nice neutral white (3500 - 4100, like most halogen lamps), what I call designer white (3000 - 3400) and warm white (2600 - 2900) that replicate incandescent light... these are seldom used for illuminating channel letters, but for backlighting a large format images, posters, etc - anything between 3500 and 5500 will do a much better job than 6500k light sources. We're working on a large airport project that is using a 12 color printing process for the digital prints, and 5300k was deemed to be the perfect white source for backlighting.

Actually, years ago, 4500 was de rigue, or whatever . It was the standard, then 6500 come along and took over the world, and now 71 is preferred by many. The choices of white often make a major difference in what is percieved, yet I would say that YYZ comments that 4500 does nothing for some colors is a stretch.

gn